Sound and television receiving system



Jan. 9, 1940.

P. c. GOLDMARK 2,186,455

SOUND AND TELEVISION RECEIVING SYSTEM Filed Oct. 24, 1956 2Sheets-Sheet1 I? 15 1g 1g 3Z7 /0 w 7% 2 11 0.5a 16 056 [1 3 24 I I l 20 I 1 RE Ii900 9MP M/X 25 27 31;; P PET Mp 10 z/ %%Jfl RE 0110 AMP AMP 41 aura/r Ql T 44/ INVENTOR.

Jafi. 9, 1940.

P. c. GOLD MARK SOUND AND TELEVISION RECEIVING SYSTEM Filed Oct. 24,1956 2 Sheets-Sheet 2 QUE OR INVENTOR.

NIYS

Patented Jan. 9, 1940 UNITED STATES PATENT OFFICE soUNn AND TELEVISIONRECEIVING v SYSTEM Application October 24,

12 Claims.

This invention relates to radio receiving systems adapted to receiveboth ultra short waves and ordinary broadcast waves, and particularly toa radio receiving system adapted for the reception of combined sound andtelevision signals as well as ordinary broadcast sound signals.

The invention has for its object generally an improved construction andarrangement of parts whereby a relatively small number of the samecoupled stages may be used, either for the reception of ultra shortwaves, or of ordinary broadcast waves with a high degree of fidelity andefliciency.

More specifically, an object of the invention is to provide a system ofcoupled stages for amplifying, heterodyning and detecting either ultrashort waves, that may carry combined sound and television signals, or anordinary broadcast wave,- that may carry sound alone, in a manner whichis both sensitive and selective.

Another object of the invention is to provide an arrangement of coupledstages that may be usedin cascade for a plurality of intermediatefrequencies resulting from the heterodyning of radio frequencies both inultra short wave region and in the ordinary broadcast region.

Another object is to provide an arrangement of cascaded heterodyningstages for operating on received radio signals of frequencies fromwidely different bands, one of which heterodyning stages may have itsheterodyning frequency discontinued when the received frequency is of apredetermined low value. v

Another object is to provide an improved coupling for heterodyningstages in cascade in a mannerv such that there are parts specificallyadapted to pass intermediate frequencies of high and low values Stillanother object is to provide an arrangement employing a cascaded pair ofheterodyning stages adapted to produce intermediate frequencies of highand low values together with means for discontinuing the het'erodyningfrequency in one of the stages when the low valued intermediatefrequency'is produced in the other.

Otherjobjects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the features of construction,combination of elements and arrangement of parts, which will beexemplified in the construction hereinafter set forth, and. thescope ofthe invention will be indicated in the claims.

For a fuller "understanding "of the nature and objects of the invention,reference should be had 1936, Serial No. 107,345

to the following detailed description taken in connection with theaccompanying drawings, in which:

Fig. 1 is a view, mainly diagrammatic, showing a radio receiving systemfor receiving both ultra short waves and ordinary broadcast waves, inaccordance with the invention;

Fig. 2 is a similar view showing a modified form of the invention shownin Fig. 1, adapted for the reception of either combined sound andtelevision signals or of ordinary broadcast sound signals; and

Fig. 3 is a diagrammatic wiring diagram showing an arrangement of stagesfor carrying into efiect the selective reception of either combined 35sound and television signals or ordinary broadcast sound signals, thelatter including a plurality of bands so as to achieve so-calledall-wave reception. When receiving radio signals over relatively widebands, or in bands with closely located stations, and a high degree ofselectivity and sensitivity is desired, it is now quite general practiceto heterodyne or beat the incoming signal with a locally generatedoscillation in order to obtain a signal having a beat or intermediatefrequency that is relatively free of interference and may be readilyamplified to the desired volume. In the case of relatively highfrequencyincoming signals, for example, those utilized in television broadcasts,it is desirable to employ a relatively high intermediate frequency inorder to obtain suflicientseparationof the so-called image frequency toenable it to be filtered out successfully. For incoming signals onsomewhat lower carrier frequencies, for example, those used in ordinarysole-sound broadcasts, a lower intermediate frequency is desirable sincemore eflicient'amplification, employing fewer stages, can be obtained atlower intermediate frequencies. Also, the higherthe intermediatefrequency, the less selective the receiver becomes. The image frequencycan still be satisfactorily eliminated despite the employment of therelatively low intermediate frequency due to the lower fre- 5 quenciesof the received signals.

, In the systems of the present invention, the advantages of a highintermediate frequency for high frequency incoming signals, for example,thoseused in television, may be secured; and 50 also the advantages of arelatively low intermediate frequency for broadcasts on ,lower frequencycarriers can beobtained. I

In accordance with the practice of the present invention, twoheterodyning stages are provided 66 in cascade so as to operate insuccession on any high valued incoming signal frequency in order to givea final desired low valued intermediate frequency. when receiving alow-valued incoming frequency, however, the stages operate as aheterodyning stage in cascade with an amplifier, a low valuedintermediate frequency being produced in the first heterodyning stage.The two heterodyning stages for this purpose have a special couplingarranged to pass high and low valued intermediate frequencies inseparate paths respectively, whereby close coupling and high efiiciencymay be obtained. When a low valued incoming frequency is received, theheterodyning in the first of these stages gives the low valuedintermediate frequency. In such case the heterodyning action of thesecond heterodyning stage is discontinued, so that amplification alonetakes place. Thus the second heterodyning-detector stage is utilized asan amplifier even though it is no longer necessary forheterodyne-detection, thus securing additional sensitivity forsole-sound broadcasts, where distance reception is desirable. Thecontrol of ,the two paths is achieved by a special switching arrangementwhich is also coordinated with the oscillating circuit of the secondheterodyning stage so as to discontinue the heterodyning frequency whenthe path pass ing the low valued intermediate frequency is selected.Thus, for example, if a low valued incoming signal frequency is beingreceived and the first heterodyning stage gives an intermediatefrequency of 456 1:12., then the second heterodyning stage would notapply any heterodyning frequency but would merely amplify and pass onthe intermediate frequency of 456 kc.

Referring now to the drawings and more particularly to- Fig. 1, IIIdenotes an antenna designed to pick up radio signal energy and to supplythe same to a suitable radio frequency amplifier I I, which may compriseone or more stages, as may be desired. The amplified radio frequency isfed into the mixer I2 of the first heterodyning stage which has anassociated oscillator indicated at I3. The resulting frequency from thefirst heterodyning stage is passed to a second stage having a mixer l4and an oscillator I5. From thence the intermediate frequency is passedto output stages which may comprise a detecting stage I6 and amplifyingand reproducing stages IT. The oscillator I3 is shown as having a pairof oscillation circuits I8 and I8 which are selectively put intooperation by means of a selector switch I9. The radio frequencyamplifier I and the oscillator I3 may be tunable, as shown for examplein Fig. 3, so as to select desired signals within the bands for whichthe receiver is designed.

The coupling for the cascaded heterodyning stages is shown as comprisinga circuit having a conductor 20, leading from the output of the stage I2'with a switch 2| in series that may be moved selectively across theterminals of coupling coils 22 and 23 which are designed respectively topass low valued and high valued intermediate frequencies. The coil 22 isin inductive association with another coil 24 while the coil 23 is insimilar inductive association with a coil 25. Coils 24 and 25 haveterminals which are selectively engaged by a switch 26 that is in serieswith the conductor 21 leading to the input of the second mixer. Theother terminals of the coils 22 and 23 have a common conductor 28leading to a plus pole of the B-supply. while coils 24 and 25 similarlyhave a common conductor 28 that leads to ground.

The second oscillator I5 applies a heterodyning frequency of constantvalue. To this end, the oscillator has a fixed tuned oscillating circuitcomprising suitable elements of inductance and capacitance, showngenerally at 30, together with a control switch 3| which when closedcauses the oscillator to function but when open causes thediscontinuance of the oscillations.

To understand the mode of operation of this form of invention, let it beassumed that an ultra short wave signal on a carrier of 50 me. is beingreceived by the antenna I and amplified at II. Then, if it be assumedthat when switch I9 puts circuit I8 into operation, a heterodyningfrequency of 53 me. is generated, this then gives an intermediatefrequency of 3 me. as output. If now switches 2| and 26 are moved to theterminals of coupled coils 23-25 and switch 3| closed, this high valuedintermediate frequency is fed into the second mixer by way of coils23-45. If now the second oscillator generates a heterodyning frequencyof 3456 kc., then a second intermediate frequency of 456 kc. will be fedinto the detecting stage I5, the output from which may be reproduced asdesired.

If again it be assumed that the radio frequency amplifier II is pickingup an ordinary broadcast signal on a frequency of 1200 kc., theoscillator I3 is changed over by means of switch I9 to circuit I8 so asto deliver a different heterodyning frequency, for example, 1656 kc.,switches 2|, 25 and 3| being now changed to the full-line positionsshown in Fig. 1. An intermediate frequency of 456 kc. is then had fromthe stage I2 which is fed by way of the coupled coils 2224 into thesecond mixer. Since switch 3| is now open, no heterodyning frequency isimpressed and this signal is merely amplified and passed on to thedetector I5. By this arrangement, it is seen that the coupled stages arein service at all times, even when receiving signals from the widelydifferent bands, as taken in the above examples.

In Fig. 2 is shown an arrangement in which stages are provided forreproducing both sound and vision signals. Here, means are providedbetween the heterodyning stages for separating sound and vision signals,whereby when receiving an ordinary broadcast band the sound signals maybe reproduced alone, or if receiving an ultra short wave, the sound andvision signals thereafter traverse separate paths; the sound path beingcommon to that of the ordinary sole-sound broadcast signals. The radiofrequency amplifying stages are here shown at H, and the firstheterodyning stage with mixer at I2. The second mixer is shown at I4 andhas coupled sound detecting and amplifying stages I and II. An IFamplifier for the vision signal is shown at 48. This vision IF amplifierfeeds into an output stage 4|. Output stage 4| may include the customarydetector to obtain the vision signals, and a suitable amplifier ifdesired. The stage 4| also may have an associated saw-toothed oscillator42 for actuating and synchronizing the scansion where a cathode ray tubeis employed.

Here, the coupling for low frequency signals comprises associated coils22-24, as in Fig. 1; for high frequency signals associated windings 33and 34 are provided, which are in series between the other terminal ofswitch 2| and the conductor 28. Inductively associated with winding 33is a winding 35 which is connected bearranged to contact one terminal ofeach of coils tween the other terminal of switch 20 and the conductor23. Also there is a winding 33 inductively associated with the winding34 that is grounded on one side and connected across the vision IFamplifier 40. By this arrangement, the ordinary broadcast signals arepassed by way of the coupling coils 22-24 into the second mixer whichoperates as a simple amplifier. If, on the other hand, the switches aremoved to put the coupled coils 33-35 and 34-43 in service, then bothheterodyning stages I2 and I4 are adapted to operate in succession whenan ultra short wave signal is received, and the sound and visioncomponents are separated and separately amplified and reproduced.

In operation, let it be assumed that combined television and soundsignals are being picked up by the antenna I and that the vision signalis on a carrier of 50 mc. and that the associated sound signal is on acarrier of 52 mc. Switch I9 will be moved to circuit I8 to have theoscillator produce a high valued heterodyning frequency of, a

for example, 55 mc.; switch 2i, being in contact with the terminal ofcoil 33, intermediate frequencies of mc. carrying the vision signal and3 mo. carrying the sound signal will then be fed to the coupling coils.By tuning these couplers, coils 33-35 may be made to pass the 3 mc.signals to the mixer I4, while the 5 mc. signals are passed into thevision IF amplifier 40. If now switch 3| puts oscillator I5 in service,its heterodyning frequency will deliver, for example, 3456 kc. Hence, asecond intermediate frequency will be fed from the second heterodyningstage at 456 kc. into the detector I6. When low frequency signal energyis being picked up, the sound reproducing stages operate as described inconnection with Fig. l. The radio frequency amplifier II and theoscillator I3 may be tunable, as shown for example in Fig. 3, so as toselect desired signals within the bands for which the receiver isdesigned.

In Fig. 3, a detailed wiring diagram is shown, having a specificarrangement of stages and windings for picking up and reproducing signalenergy from a plurality of bands including a sound-television band.Here, each stage and the interstage coupling comprise parts coordinatedso that they may be simultaneously changed over and receive any desiredsignal in a particular band in a manner which is both sensitive andselective. Here, the antenna I0 has in series with it a selecting switchIIO adapted to make contact with the respective terminals of a pluralityof coils here shown, by way of example, as four sets of coils which havea common connection to ground at 9. These four coils are shown aswindings III, H2, H3, and H4, and have corresponding inductivelyassociated windings III H2, H3, and 4'. These latter have terminals thatare selectively contacted by the blade of a switch II5, the other sideof these coils having a common conductor II5 leading through suitableimpedance to an automatic volume control or other source of potential.These coils have a variable tuning condenser I I1 that is connectedbetween the switch H5 and ground, the switch being connected to thecontrol element or grid of an amplifying tube II3. From the plateelement of tube III! a conductor II9 leads to a selecting switch I ofthe mixer I 2. This stage has coils arranged as counterparts of those inthe radio frequency amplifying stage in order similarly to pass signalsfrom the several bands that may be picked up. Accordingly, switch I20 isshown as I ciated wtih the oscillator I3.

or windings I2I, I22, I23, and I24 that have a common ground connectiona. The inductively associated component windings are shown at I2I, I22,I23, and I24, one terminal of each of the latter being contacted bymeans of a switch I25, the other terminal having a common connection I23leading to the automatic volume control. These coils are similarly tunedby means of avariable condenser I21 that is connected between the switchI25 and ground. The switch in turn is connected to the control elementor grid of a tube I23 which is preferably of the multicontrol electrodetype; an extra grid being here shown as connected by conductor I23 to aswitch I30. This latter is arranged selectively to contact terminals ofsections of inductance asso- These sections of inductance comprisewindings I3I, I 32, I33, and I34, there being corresponding inductivelyassociated windings I3I, I32, I33, and I34. windings I3I and I3I have acommon connection through a condenser I3I" to ground, there beingcondensers I 32", I33", and I34", similarly connected for each of theother sets of windings. The windings I 3|, I 32', etc., are selectivelyconnected by means of a switch I35 with a plate element of the tube I38,the grid element being similarly connected by a conductor I36 to theconductor I29. A tuning condenser I31 for the oscillator is connectedbetween ground and the conductor I29. For convenience in tuning, thecondensers II1, I21, and I 31 are preferably ganged together so as to bemoved simultaneously. The plate element of tube I33 is also preferablyconnected by means of a conductor I with a pole of the B-supply or othersource of potential.

The conductor 20 is shown in this figure as leading from the plateelement of tube I23 to the switch 2|, this switch being movablealternately to the terminals associated wth the coupled coils 22--24 orwith coils33-35 and 34-36, coils 33 and 34 being in series. Switch 26,which swings across the terminals associated with windings 24 and 35, isconnected to a control grid of the tube I40 of thesecond heterodyningstage which is also preferably of the multi-control electrode type andadapted to serve as a combined oscillator and amplifier and is arrangedto employ so-called electron coupling." By such an arrangement thesingle tube serves both as oscillator and amplifier; hence there are notubes of the system out of service when the stage operates solely as anamplifier. From the plate element of tube I40 a conductor I4I leads toone terminal of the coupling inductance I42, the other terminal of whichis connected by way of conductor I43 to the B- supply or other source ofpotential. Shunted across the terminals of inductance I42 is a condenserI44 for tuning purposes.

Where the tube I40 is of the pentagrid converter variety, there isconnected to one of the oscillator plate grids a conductor I45 which hasin series a resistance I 45 and the switch 3|, the whole beinginterposed between such grid and the conductor I43. Between a secondoscillatorgrid and a point leading to ground is connected a condenserI41, an inductance I43 and a second condenser I43, all in series, theinductance I43 and condenser I49 being preferably shunted by means of atrimming condenser I50 employed for tuning purposes. This, condenser isonly variable over small limits; the stage being a fixed oscillator.Between conductor I45 and condenser I43 are connected another condenserI5I and ing ductance I52 in series the latter inductance beinginductively associated with inductance I43.

Inductively associated with the winding I42 is a winding I in order thatthis heterodyning and 3 11 stage may be coupled to the subsequent mdetecting and amplifying stages, here shown as in Fig. 2, and denoted I3and II, respectively. To

the coil 35 there is also shown coupled and IF amplifying stage 40. Theoutput of this stage 1 passes into a suitable detecting and output stage4I, with which a suitable saw tooth oscillator 42 may be associated, asin Fig. 2.

In the arrangement shown in Fig. 3, it is not only desirable to gangtogether the condensers III, I 21, and I3! for simultaneous operation,but it is also desirable to gang together the switches H0, H5, I20, I25,I30, and I35 for simultaneous operation and to have switches 2|, 25, 3|,and 32 ganged together and connected to the switches H0, H5, I20, I25,I30, and I35 with a mechanical lost-motion connection of a charactersuch that when switch I I0 is moved to engage the terminal of coil I II, then switches of the group 2|, 25, 3| will move into engagement withthe 35 terminals of coils 33-34, 35-36 and of connection I46 andconnection I41, but when switch 0 is moved to engage with any of theother terminals of its set, switches 2I, 26, 3|, and 32 are moved intotheir alternate positions and remain there; switch 3| discontinuing theheterodyning frequency for such positions and switch 32 discontinuingthe power for the vision part of the receiver. Any suitable mechanicalconnection that effects such movements may be employed,

and since such are known, the showing of the same is omitted from thedrawings in the interests of clearness of illustration but is assumed tobe present in the description of the operation given below.

In operation, let it be assumed that coupled coils III-III and I2I-I2I"pass the band of ultra'short waves, for example, the band from 30 to 100mc.; that coils II2-II2' and I22-I22' pass a band of ordinary broadcastwaves, for ex- 5 ample, the band from 10 to 30 mc.; that coils II3-II3and I23-I23' pass an adjacent band of ordinary broadcast waves, forexample, the band from 1.5 to 10 mc.; and that coils I I4-I I4 andI24-I24' pass another adjacent band of 543 ordinary broadcast waves, forexample, the band from 540 kc. to 1.5 mc.

Then, when switch I"! is moved to the fullline position shown in thedrawings, coils III- III, l2I-I2I' are in service, also coils I3I-I3I'and coils 33-35 and 34-35. The oscillating circuits associated with tubeI40 will also be operating by reason'of the closed position of switch3|. If new the ganged condensers be tuned so as 5 to pick up a combinedsound and television signal on carriers, for example, of 50 mc. for thevision signal and 52 mc. for the ,sound signal, this set of signals willbe passed through the top sets of coils shown and heterodyned in thetube I28 by the frequency supplied by the oscillator 5 having tube I38.If this oscillator is made to track the sound signal at 3 mc., thelocally generated frequency provided by coils I3l-I3I' and condenser I31is 55 me. An intermediate frequency for sound of 3 mc. is fed into coils33 and 34 while an intermediate frequency for vision of 5 mc. issimilarly fed into these coils. By tuning these coils with capacitanceelements as shown, the 3 mc. intermediate frequency may be made to passby way of coupled coils 33-35 to the second mixer tube at I43 while the5 mc.

intermediate frequency is passed by way ofcoupiedcoilsfl-Jltothevisionamplifyingand reproducing stages 40 and 4|.

lfwhenswitchfliscloeedthemixerfll generates a locally generatedfrequency of 3456 6 kc., then a second intermediate frequency of 456 kc.may be led 0! and fed into the sound detecting and reproducing stages Itand II.

It now switch M0 is moved to contact with a terminal of coil H4 (or anyone of coils H2, III, 10 and H4) switches II5, i2l, I25, I30, and I35will move to similar positions; switches 2I and 25 will be moved totheir alternate positions; and switch 3| will be moved to open position.The lower tracking frequency of the oscillating stage 15 having tube I38is, of course, determined by the design and is such asto give thedesired low valued intermediate frequency when receiving an ordinarybroadcast sound signal. Let it be assumed, for example, that a soundsignal of 810 U kc. is to be picked up, then the tuning is effected bythe simultaneous movement of condensers II'I, I21 and I3! which whendone causes the oscillator to track at a frequency giving the desiredlow valued intermediate frequency. In the example given, if thisintermediate frequency be 456 kc., then the heterodyning frequency is1266. This low valued intermediate frequency is, of course, passedthrough coupling coils 22-24 into the second mixing tube I40 which nowoperates as a simple amplifier since switch 3I is open; switch 32 beingalso open. This signal is then detected and further amplified andreproduced at H. Of course, additional intermediate frequencyamplification may be employed between the sec- 35 0ndheterodyne-detcctor stage and the final detector I6, as is customary inthe art, in order to secure added sensitivity and volume. This may alsobe done in Figs. 1 and 2.

The use of a combined mixing and oscillating 4o tube at I40 is seen tosimplify the second heterodyning stage employed in accordance with theinvention, since neither tuning of the oscillating nor of the receivingcircuits of this stage is employed. When this stage operates as an am- 5pliiier, it receives an intermediate frequency of constant valuewhatever the frequency of the incoming signal, which intermediatefrequency, in the example given above, is 456 kc. The receivedintermediate frequency is also constant in value when the stage isoperating as a heterodyning stage, which, in the example given above, is3 mc. when any ultra short wave is being received.

Since certain changes may be made in the 55 above construction anddifferent embodiments of the invention could be made without departingfrom the scope thereof, it is intended that all matter contained in theabove description or shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. In a radio receiving system adapted for the reception of both a bandof ultra short waves and a band of ordinary broadcast waves, thecombination comprising means for receiving incoming radio frequencysignal energy and selecting a radio frequency from one of said bands,means in- 70 eluding a first heterodyning stage coupled to saidreceiving means for converting the radio frequency into an intermediatefrequency, means including a second heterodyning stage connected toreceive said intermediate frequency, sound reproducing output meanscoupled to said second heterodyning stage, coupling means for couplingsaid heterodyning stages in cascade and having portions for separately111811 valued and low valued intermediate frequencies, said high valuedportion including two sets of coupling coils, only one of which isconnected to said second heterodyning stage, an independent output meansconnected to the other of said sets of coupling coils, switch meanshaving members for selecting a path through said coupling means, and acoordinated member associated with said second heterodyning stage fordiscontinuing the heterodyning frequency when a low valued intermediatefrequency is being passed.

2. In a radio receiving system adapted for the reception of both a bandof ultra short waves and a band of ordinary broadcast waves, thecombination comprising means for receiving incoming radio frequencysignal energy and selecting and amplifying a radio frequency from one ofsaid bands, means including a first heterodyning stage coupled to saidreceiving means for converting the radio frequency into an intermediatefrequency, means including a second heterodyning stage connected toreceive said intermediate frequency, sound reproducing output meanscoupled to said second heterodyning stage, coupling means for couplingsaid heterodyning stages in cascade and having portions for passingseparately relatively high valued and relatively low valued intermediatefrequencies, said high valued portion including two sets of couplingcoils, only one of which is connected to said second heterodyning stage,an independent output means connected to the other of said sets ofcoupling coils, switching means arranged for selecting a path throughsaid coupling means, and a second switching means associated with saidsecond heterodyning stage connectedwith said first-named switch membersso that the heterodyning frequency is discontinued when a low valuedintermediate frequency is being passed.

3. In a radio receiving system adapted for the reception of ultra shortwaves that carry associated sound and television signals and ordinarybroadcast waves that carry sound signals alone, the combinationcomprising a radio frequency amplifying stage having input and outputcoupling coils adapted for the passage of signals within a band of ultrashort waves and a plurality of sets of input and output coils adaptedfor the passage of signals within a plurality of ordinary broadcastbands, a first heterodyning stage having a plurality of sets of couplingcoils associated with said first-named coupling coils arranged toconvert ultra short waves carrying sound and television signals intohigh valued intermediate frequencies and ordinary broadcast waves into acommon low valued intermediate frequency, a second heterodyning stagehaving associated sound amplifying and reproducing means coupled toreceive its output, vision stages having vision amplifying andreproducing stages, coupling means interposed between said heterodyningand vision stages in a manner such that said second heterodyning stageand said vision stages are each cascaded upon said first heteroryningstage, said coupling means being provided with portions for the passageof said high valued and low valued intermediate frequenciesrespectively, said high valued portion only including a coupling to saidvision stages, means for simultaneously tuning said radio frequencyamplifying stage and said first heterodyning stage, and

switchmeansforselectingapaththroughsaidcoupling means.

4. In a radio receiving system adapted for the reception of ultra shortwaves that carry associated sound and television signals and ordinarysound broadcast wavesthat carry sound signals alone, the combinationcomprising a radio frequency amplifying stage having inputandoutputcoupling coils adapted for the passage of signals within a bandof ultra short waves and a plurality of sets of input and output coilsadapted for the passage of signals within a plurality of ordinarybroadcast bands, a first heterodyning stage having a plurality of setsof coupling coils associated ,with said output coupling coils arrangedto convert associated sound-television signals on ultra short waves intohigh valued intermediate frequencies and ordinary sound broadcast wavesinto a common low valued intermediate frequency, a second heterodyningstage having associated sound amplifying and reproducing means coupledto receive its output, vision stages having vision amplifying andreproducing stages, coupling means interposed between said heterodyningand vision stages in a manner such that said second heterodyning stageand said vision stages are each cascaded upon said first heterodyningstage, said coupling means being provided with portions for the passageof said high valued and low valued intermediate frequenciesrespectively, said high valued portion only being coupled to said visionstages, means for simultaneously tuning said radio frequency amplifyingstage and said first heterodyning stage, switch means for selecting apath through said coupling means provided with a mechanical couplingwith said tuning means and arranged to establish the path for thepassage of the low, valued intermediate frequency to the secondheterodyning stage for all ordinary broadcast bands and a path for thehigh' valued intermediate frequency for the soundtelevision band, and acoordinated switch associated with said second heterodyning stage fordiscontinuing the heterodyning frequency when the low valuedintermediate frequency is being passed. a

5. A radio receiver adapted to receive and reproduce signals on carrierswithin widely separated frequency bands comprising, in combination, afirst heterodyning stage including an oscillator, said heterodyningstage being adapted to convert a signal on a relatively high frequencycarrier to a relatively high-valued intermediate frequency and toconvert a signal on a relatively low frequency carrier to a relativelylow-valued intermediate frequency, a second heterodyning stage fed fromsaid first heterodyning stage and including an oscillator, and detectingand reproducing stages fed from said second heterodyning stage, saidsecond heterodyning stage being adapted to heterodyne a high-valuedintermediate frequency signal supplied from said first heterodyningstage to convert it to a low-valued intermediate frequency signal forreproduction in the subsequent stages, and adapted alternatively toamplify a low-valued intermediate frequency signal supplied from saidfirst heterodyning stage by the discontinuing of the oscillatorfrequency so that the low-valued intermediate frequency signal may bereproduced in the subsequent stages.

6. A radio receiver adapted to receive and reproduce signals on carrierswithin widely separated frequency bands comprising, in combinalect asignal within a desired frequency band, a first heterodyning stage fedfrom said radio frequency amplifier and including an oscillator. saidoscillator being tunable to convert signals in a selected relativelyhigh frequency band to a selected relatively high-valued intermediatefrequency and to convert signals in a selected relatively low frequencyband to a selected relatively low-valued intermediate frequency, asecond heterodyning stage including an oscillator associated therewith,means for feeding said second heterodyning stage with signals from saidfirst heterodyning stage, detecting and output stages fed from saidsecond heterodyning stage, and means for supplying a heterodyningfrequency to said second heterodyning stage from its associatedoscillator when said high-valued intermediate frequency is supplied toit and for discontinuing the heterodyning frequency when said low-valuedintermediate frequency is supplied to it.

'7. A radio receiver adapted to receive sound broadcast signals on acarrier within a sound broadcast band and sound-television signals on apair of associated carriers within a television broadcast band whichcomprises, in combination, a radio frequency amplifier tunable to eithersound broadcast signals or to associated pairs of sound and televisionsignals, a first heterodyning stage fed from said radio frequencyamplifier and including an oscillator, said oscillator being tunable toconvert sound broadcast signals within a sound broadcast band to aselected relatively low-valued intermediate frequency and to convert anassociated pair of sound-television signals within a televisionbroadcast band to an associated pair of relatively high-valuedintermediate frequency signals, sound stages including a secondheterodyning stage having an associated oscillator and detecting andsound reproducing stages, means operable to supply said sound stageswith either said low-valued intermediate frequency signal or the soundcomponent of said high-valued intermediate frequency signals,-said soundstages being adapted to reproduce signals received at said low-valuedintermediate fre-' quency when the frequency produced by the lastnamedoscillator is discontinued and to convert the said high-valuedintermediate frequency signal of the said sound component to saidlowvalued intermediate frequency signal for reproduction thereof whenthe oscillator frequency is applied to the second heterodyning stage,means for discontinuing the heterodyning frequency of said sound stageswhen they are supplied with said low-valued intermediate frequencysignal,

television stages adapted to receive and reproduce television signals,and means for supplying said television stages with the televisioncomponent of the said high-valued intermediate frequency sig:

nals for reproduction thereof.

8. A radio receiver adapted to receive and reproduce signals on carrierswithin a plurality of frequency bands comprising, in combination, a.first heterodyne-detector stage having an oscillator associatedtherewith, said heterodyne-detector stage being tunable to convertreceived signals within a relatively high frequency band to a selectedrelatively high-valued intermediate frequency signal and to convertreceived signals within a relatively low frequency band to a selectedrelatively low-valued intermediate frequency signal, a secondheterodyne-detector stage connected to be fed with signals from said firt tion, a radio frequency amplifier tunable to seheterdoyne-detectorstage and having an oscillator of substantially fixed fr q encyassociated therewith, detecting and output stages connected to be fedfrom said second heterodyne-detector stage, and means for supplyin anddiscontinuing the oscillation frequency from the second-named oscillatorto said second heterodyne-detector stage, said secondheterodyne-detector stage being designed and constructed, when suppliedwith said oscillation frequency, to convert a high-valued intermediatefrequency signal fed thereto to a low-valued intermediate frequencysignal having substantially the same frequency as that of thefirst-mentioned relatively low-valued intermediate frequency signal forreproduction in the subsequent stages, and alternatively to amplify alow-valued intermediate frequency signal fed thereto from the firstheterodyne-detector stage when the said oscillation frequency isdiscontinued so that the low-valued intermediate frequency signal may bereproduced in the subsequent stages.

9. A radio receiver adapted to receive solesound broadcast signals oncarriers within a sound broadcast band and associated sound andtelevision signals on associated carriers within a television broadcastband which comprises, in combination, a first heterodyne-detector stageincluding an oscillator and adapted to receive sig- 'nals at broadcastfrequencies, said heterodynedetector stage being tunable to convert asolesound signal within a sound broadcast band to a relativelylow-valued intermediate frequency signal and to convert an associatedpair of sound and television signals within a television broadcast bandto an associated pair of relatively highvalued intermediate frequencysignals, sound stages including a second heterodyne-detector stagehaving an associated oscillator, and detecting and sound reproducingstages fed from said second heterodyne-detector stage, means for feedingsaid second heterodyne-detector stage with sound signals from said firstheterodyne-detector stage, means for supplying and discontinuing theoscillation frequency from the second-named oscillator to said secondheterodyne-detector stage, said second heterodyne-detector stage beingadapted, when supplied with said oscillation frequency, to convert ahigh-valued intermediate frequency sound signal fed thereto to alow-valued intermediate frequency sound signal having substantially thesame frequency as that of the first-mentioned relatively low-valuedintermediate frequency signal for reproduction in the subsequent stages,and adapted alternatively to amplify a low-valued intermediate frequencysound signal fed thereto from the first heterodyne-detector stage whenthe said oscillation frequency is discontinued so that the low-valuedintermediate frequency sound signal may be reproduced in the subsequentstages, television stages adapted to receive and reproduce television.signals fed thereto from said first heterodyne-detector stage, and meansfor feeding television signals from the first heterodyne-detector stageto said television stages.

10. In a radio receiving system adapted for the reception of both a bandof ultra short waves and a band of longer waves, the combinationcomprising means for receiving incoming radio frequency signal energyand selecting a radio frequency from one of said bands, means includinga first heterodyning stage coupled to said receiving means forconverting the radio frequency into an intermediate frequency, thesecond-named means being tumble to convert a radio frequency within saidultra short wave band to a relatively highvalued intermediate frequencyand, alternatively, to convert a radio frequency within said longer Waveband to a relatively low-valued intermediate frequency, a secondheterodyning stage constructed to convert a signal at said relativelyhigh-valued intermediate frequency to said relatively low-valuedintermediate frequency, detecting and output means coupled to saidsecond heterodyning stage, coupling means interposed between saidheterodyning stages for coupling them in cascade, said coupling meanshaving a plurality of paths for passing selectively relatively high andrelatively low valued intermediate frequencies from said first stage tosaid second stage, switch means associated with said coupling means foralternatively selecting one of said paths through said coupling means,and a coordinated member associated with said second heterodyning stagefor discontinuing the heterodyning frequency when a low valuedintermediate frequency is being passed, said second heterodyning stagebeing constructed to function as an amplifying stage when theheterodyning frequency therefor is discontinued.

11. A radio receiver adapted to receive and reproduce signals oncarriers within a plurality of frequency bands comprising, incombination, a first heterodyne-detector stage having an oscillatorassociated therewith, said heterodynedetector stage being tunable toconvert a received signal within a relatively high frequency band to arelatively high-valued intermediate frequency and to convert a receivedsignal within a relatively low frequency band to a relatively lowvaluedintermediate frequency, a second heterodyne-detector stage fed from saidfirst heterodyne-detector stage and including an oscillator, detectingand reproducing stages fed from said second heterodyne-detector stage,means for alternatively rendering the second-named oscillator operativeand inoperative, said second heterodyne-detector stage being constructedand adapted when the second-named oscillator is rendered inoperative toamplify a low-valued intermediate frequency signal supplied from saidfirst heterodyne-detector stage for reproduction in the subsequentstages and, alternatively, to

heterodyne a high-valued intermediate frequency signal supplied from thefirst heterodyne-detector stage to convert it to the last-mentionedlowvalued intermediate frequency for reproduction in the subsequentstages when the second-named oscillator is rendered operative.

12. A radio receiver adapted to receive solesound broadcast signals oncarriers within a sound broadcast band and associatedsound-andtelevision signals on associated carriers within a televisionbroadcast band which comprises, in combination, a firstheterodyne-detector stage including an oscillator and adapted to receivesignals at broadcast frequencies, said heterodyne- ,detector stage beingtunable to convert asolesound signal within a sound broadcast band to arelatively low-valued intermediate frequency signal and to convert anassociated pair of sound and television signals within a televisionbroadcast band to an associated pair of relatively highvaluedintermediate frequency signals, sound stages including a secondheterodyne-detector stage having an associated oscillator, detecting andsound reproducing stages fed from said sec ond heterodyne-detectorstage, means for feeding said second heterodyne-detector stage with thesound signals from said first heterodynedetector stage, means foralternatively'rendering the second-named oscillator operative andinfirst heterodyne-detector stage, and means for feeding televisionsignals from the first heterodyne-detector stage to said televisionstages.

PETER O. GOLDMARK.

